Hello, could someone correct my mistake again pls?

Also this one on 10FEB:
Thank you so much!
Q:
Write a letter to complain about a situation in which some adolescents let their dogs run wildly causing dangerous.
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A:
Dear Sir,
I am writing to complain about a recently situation that some adolescents let their dogs run wildly causing dangerous in the central park at night.
Usually I go to central park for running training everyday about 20:00 and this is no problem regarding the dogs and the dog's owner before. However, some adolescents came to the park and let their dogs run wildly in the past few months until now. Sometimes their dogs will hit people while the peoples walking or running in the park even bark or bite people.
I suggest that the park management office should issue some policy to protect the people inside. For example, the guardian should not let the people take their dogs inside if their dog without a mask or rope, or divide some area in the park which dog is not allowed.
Your help would be appreciated
Regards
Assman